OpenHarmony：全流程讲解如何编写GPIO平台驱动以及应用程序 原创 精华

struct GpioMethod {
    int32_t (*request)(struct GpioCntlr *cntlr, uint16_t local);                 // 【预留】
    int32_t (*release)(struct GpioCntlr *cntlr, uint16_t local);                 // 【预留】
    int32_t (*write)(struct GpioCntlr *cntlr, uint16_t local, uint16_t val);
    int32_t (*read)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *val);
    int32_t (*setDir)(struct GpioCntlr *cntlr, uint16_t local, uint16_t dir);
    int32_t (*getDir)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *dir);
    int32_t (*toIrq)(struct GpioCntlr *cntlr, uint16_t local, uint16_t *irq);    // 【预留】
    int32_t (*setIrq)(struct GpioCntlr *cntlr, uint16_t local, uint16_t mode, GpioIrqFunc func, void *arg);
    int32_t (*unsetIrq)(struct GpioCntlr *cntlr, uint16_t local);
    int32_t (*enableIrq)(struct GpioCntlr *cntlr, uint16_t local);
    int32_t (*disableIrq)(struct GpioCntlr *cntlr, uint16_t local);
}
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root {
    device_info {
        platform :: host {
            device_gpio :: device {
                device0 :: deviceNode {                         // GPIO控制器信息描述
                    policy = 2;                                 // 对外发布服务，必须为2，用于定义GPIO管理器的服务
                    priority = 50;
                    permission = 0644;
                    moduleName = "HDF_PLATFORM_GPIO_MANAGER";   // 这与drivers/hdf_core/framework/support/platform/src/gpio/gpio_service.c的g_gpioServiceEntry.moduleName对应，它主要负责GPIO引脚的管理
                    serviceName = "HDF_PLATFORM_GPIO_MANAGER";
                }
                device1 :: deviceNode {
                    policy = 0;                                 // 等于0，不需要发布服务
                    priority = 55;                              // 驱动驱动优先级
                    permission = 0644;                          // 驱动创建设备节点权限
                    moduleName = "linux_gpio_adapter";          // 用于指定驱动名称，必须是linux_adc_adapter，与drivers/hdf_core/adapter/khdf/linux/platform/gpio/gpio_adapter.c对应
                    deviceMatchAttr = "";                       // 用于配置控制器私有数据，不定义
                }
            }
        }
    }
}
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#include "../../samples/b03_platform_device_gpio/config/device_info.hcs"
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// GPIO设置为输出
ret = GpioSetDir(m_gpio_id, GPIO_DIR_OUT);
if (ret != 0) {
    PRINT_ERROR("GpioSetDir failed and ret = %d\n", ret);
    return -1;
}

// GPIO输出电平
ret = GpioWrite(m_gpio_id, m_gpio_value);
if (ret != 0) {
    PRINT_ERROR("GpioWrite failed and ret = %d\n", ret);
    return -1;
}
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// GPIO设置为输出
ret = GpioSetDir(m_gpio_id, GPIO_DIR_IN);
if (ret != 0) {
    PRINT_ERROR("GpioSetDir failed and ret = %d\n", ret);
    return -1;
}

// 读取GPIO引脚的电平
ret = GpioRead(m_gpio_id, &m_gpio_value);
if (ret != 0) {
    PRINT_ERROR("GpioRead failed and ret = %d\n", ret);
    return -1;
}

printf("GPIO Read Successful and GPIO = %d, value = %d\n", m_gpio_id, m_gpio_value);
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import("//build/ohos.gni")
import("//drivers/hdf_core/adapter/uhdf2/uhdf.gni")

ohos_executable("rk3568_gpio_test") {
  sources = [ "gpio_test.c" ]
  include_dirs = [
    "$hdf_framework_path/include",
    "$hdf_framework_path/include/core",
    "$hdf_framework_path/include/osal",
    "$hdf_framework_path/include/platform",
    "$hdf_framework_path/include/utils",
    "$hdf_uhdf_path/osal/include",
    "$hdf_uhdf_path/ipc/include",
    "//base/hiviewdfx/hilog/interfaces/native/kits/include",
    "//third_party/bounds_checking_function/include",
  ]

  deps = [
    "$hdf_uhdf_path/platform:libhdf_platform",
    "$hdf_uhdf_path/utils:libhdf_utils",
    "//base/hiviewdfx/hilog/interfaces/native/innerkits:libhilog",
  ]

  cflags = [
    "-Wall",
    "-Wextra",
    "-Werror",
    "-Wno-format",
    "-Wno-format-extra-args",
  ]

  part_name = "product_rk3568"
  install_enable = true
}
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"b03_platform_device_gpio/app:rk3568_gpio_test",
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hb set -root .
hb set
#选择lockzhiner下的rk3568编译分支。
hb build -f
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# rk3568_gpio_test -g 13 -i
gpio id: 13
gpio dir: in
gpio value: 0
GPIO Read Successful and GPIO = 13, value = 1
#
# 
# rk3568_gpio_test -g 13 -o
gpio id: 13
gpio dir: out
gpio value: 0
#
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